Molasses is a sugar processing wastes containing sugar high enough to potentially be used as fermentation media. Fermentation of molasses to produce ethanol be an effort to reduce the amount of waste and meet the needs of fuel oil (BBM) is increasing Ethanol production can be done with the help of yeast. One of the commonly used yeast is Saccharomyces sp. Given the importance of the role of yeast in ethanol production, it is necessary to be an endogenous yeast isolation from molasses. The purpose of this study was to isolate yeast from molasses and determine the ability of yeasts isolated from molasses in the production of ethanol.

This research includes the isolation and identification of macroscopic and microscopic yeasts isolated from molasses. Furthermore, the best test the ability of yeast isolated from molasses to produce ethanol by fermentation time variation consisting of 3, 4, 5, 6, and 7 days. Each repetition as much as 2 times, then ethanol fermentation results analyzed using gas chromatography.

Isolation results of this study were obtained 2 isolates of yeast, they were Kh1 yeast and Kh2 yeast. The production of ethanol from molasses obtained the result Kh2 yeast produces ethanol level which higher than Kh1 yeast. Based on the analysis result in the treatment of fermentation by Kh2 yeast with variations 3, 4, 5, 6, and 7 days were obtained ethanol levels successively are 10,995%, 8.735%, 20.355%, 43.435% and 9.965%. The best treatment is the fermentation for 6 days which obtaines yield 97.47%, and fermentation efficiency 88.17%. It is show that the Kh2 yeast has the potential and function in the production of ethanol from molasses.